Anatomical variations of the human occipital condyles

Occipital condyles, located at the inferior sides of lateral parts of occipital bone, are important structures that connect the cranium and the vertebral column. Their size, shape, location and, also, their congruence with superior articular facets of the atlas vertebra are of great importance for the stability of craniovertebral junctions. The progress in medical diagnostic and surgical techniques in the area of foramen magnum, requires the knowledge regarding anatomical aspects of this region. The purpose of this study was to evaluate the measurements of the occipital condyles, as well as to analyse the variations in the shape of the condyles and their position in relation to the foramen magnum. This study included 25 adult human skulls (11 male and 14 female) from the Osteological collection of the Department of Anatomy at Medical Faculty in Novi Sad. Nine parameters, which define morfological properties of the occipital condyles, were measured using Vernier caliper. Also, the shape and location of the condyles, as well as the narrowness of the foramen magnum were described. Our findings show that length of the left occipital condyle, as well as distance between the posterior top of the left occipital condyle and basion are statistically greater in male crania, comparing to female crania. According to the shape of the occipital condyles, we classified them in seven groups. Predominant type is oval shaped. The condylar foramen is bilaterally present in 36 % and the occipital condyles bilaterally protrude the foramen magnum in 40 % of analyzed crania. Morphometric analysis of the occipital condyles showed variations in their size, shape, presence of condylar canal and relation to the foramen magnum.